336 The Wolmrn Pot-Culturp. Experiments^ 1910-11-12. 



therefore, in view of earlier observations, to attribute the 

 incubation period directly to the influence of lime, and it is 

 quite possible that temperature was a more determining factor. 

 By May, 1912, it was noticeable that the "untreated" sets 

 were the most forward, and this continued until June, when 

 the first two sets with addition of lime were quickly making 

 up to them, the other three sets, however, being behind. By 

 July 13, the first two " limed " sets were well ahead of the 

 "untreated," and the next two also l>etter. As the plants 

 matured, it was seen that the applications of lime had length- 

 ened the straw and also shown a tendency to lengthen the ear. 

 This is in direct contrast to what had been noticed as the result 

 of adding magnesia, for this latter caused shortening of both 

 straw and ear. At harvest the following results were 

 obtained : — 



These results are directly in confirmation of previous ones. 

 Whether the full effects of the new additions of lime have had 

 time yet to tell is open to question — as was the case with the 

 first applications of lime in 1909. And this may, possibly, 

 account for the somewhat anomalous results of set 6. At all 

 events, it is brought out that lime added up to 4 per cent, 

 (the magnesia remaining at 2*29 per cent.) has given an increase 

 both of corn and straw over the " untreated " set. And, what 

 is most important, it has been shown that the addition of lime 

 after the ratio 1:1 has been exceeded is not attended with the 

 same toxic results that followed the similar addition of 

 magnesia, and it may be concluded, accordingly, that the 

 proportion of lime in a soil may quite well exceed that of 

 magnesia without any detrimental effects following, whereas 

 if the magnesia exceeds the lime the cropping propei'ties are 

 likely to suffer. 



5. Plot Experiment. 1911 and 1912. 



After obtaining in 1910 the results set out, it was considered 

 desirable to try the experiment with magnesia on a larger scale, 

 for it might well be asked whether the striking results obtained 

 in pot-culture might not be di;e to the particular conditions of 



